From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 163A2C282D7 for ; Wed, 30 Jan 2019 18:21:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E466A21473 for ; Wed, 30 Jan 2019 18:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733030AbfA3SVm (ORCPT ); Wed, 30 Jan 2019 13:21:42 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:59662 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732918AbfA3SVm (ORCPT ); Wed, 30 Jan 2019 13:21:42 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AAEA180D; Wed, 30 Jan 2019 10:21:41 -0800 (PST) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 312693F557; Wed, 30 Jan 2019 10:21:40 -0800 (PST) Date: Wed, 30 Jan 2019 18:21:37 +0000 From: Will Deacon To: Nicolas Boichat Cc: Robin Murphy , Joerg Roedel , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Catalin Marinas , stable@vger.kernel.org Subject: Re: [PATCH] iommu/io-pgtable-arm-v7s: only kmemleak_ignore L2 tables Message-ID: <20190130182137.GN18558@fuggles.cambridge.arm.com> References: <20190128094301.151252-1-drinkcat@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190128094301.151252-1-drinkcat@chromium.org> User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 28, 2019 at 05:43:01PM +0800, Nicolas Boichat wrote: > L1 tables are allocated with __get_dma_pages, and therefore already > ignored by kmemleak. > > Without this, the kernel would print this error message on boot, > when the first L1 table is allocated: > > [ 2.810533] kmemleak: Trying to color unknown object at 0xffffffd652388000 as Black > [ 2.818190] CPU: 5 PID: 39 Comm: kworker/5:0 Tainted: G S 4.19.16 #8 > [ 2.831227] Workqueue: events deferred_probe_work_func > [ 2.836353] Call trace: > ... > [ 2.852532] paint_ptr+0xa0/0xa8 > [ 2.855750] kmemleak_ignore+0x38/0x6c > [ 2.859490] __arm_v7s_alloc_table+0x168/0x1f4 > [ 2.863922] arm_v7s_alloc_pgtable+0x114/0x17c > [ 2.868354] alloc_io_pgtable_ops+0x3c/0x78 > ... > > Fixes: e5fc9753b1a8314 ("iommu/io-pgtable: Add ARMv7 short descriptor support") > Signed-off-by: Nicolas Boichat > --- > > I only tested this on top of my other series > (https://patchwork.kernel.org/patch/10720495/), but I think the same fix > applies. I'm still a bit confused as to why this only shows up now, as IIUC, > the kmemleak_ignore call was always wrong with L1 tables. Yes, I managed to reproduce this on top of -rc4 (see below). I suspect you /are/ the intersection of people using v7s w/ kmemleak, so this has just lingered and never been hit until now. For the patch (assuming this is going via Joerg): Acked-by: Will Deacon Will --->8 [ 0.124473] kmemleak: Trying to color unknown object at 0xffff8000042d8000 as Black [ 0.125312] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc4-00012-g40b114779944 #1 [ 0.126181] Hardware name: linux,dummy-virt (DT) [ 0.126680] Call trace: [ 0.126950] dump_backtrace+0x0/0x140 [ 0.127346] show_stack+0x14/0x20 [ 0.127706] dump_stack+0x90/0xb4 [ 0.128066] paint_ptr+0x94/0xa8 [ 0.128417] kmemleak_ignore+0x54/0x60 [ 0.128991] __arm_v7s_alloc_table+0x6c/0x240 [ 0.129661] arm_v7s_alloc_pgtable+0x10c/0x188 [ 0.130359] alloc_io_pgtable_ops+0x44/0xb0 [ 0.131006] arm_v7s_do_selftests+0x84/0x4bc [ 0.131663] do_one_initcall+0x74/0x178 [ 0.132253] kernel_init_freeable+0x188/0x220 [ 0.132923] kernel_init+0x10/0x100 [ 0.133460] ret_from_fork+0x10/0x18 [ 0.142102] arm-v7s io-pgtable: self test ok